An example of threaded python code. Starts with a number of seconds entered by the user, then spawns a thread to countdown those seconds and another to prompt the user to add more seconds to the clock. Demonstrates one thread manipulating another.

countdown.py

import threading
import time

(i, seconds) = (0, 5)


def countdown():
    global seconds, i
    while i < seconds:
        time.sleep(1)
        i = i + 1
    print
    print "boom!"


def menu():
    global seconds, i
    entry = raw_input("seconds to add: ")
    while entry != "quit":
        if entry == 'sec':
            print seconds
        elif entry == 'sec left':
            print seconds - i
        else:
            try:
                seconds = seconds + int(entry)
            except ValueError:
                pass
        entry = raw_input("seconds to add: ")

c = threading.Thread(target=countdown)
c.start()
m = threading.Thread(target=menu)
m.daemon = True
m.start()